I'm working on a project using Angular Material, a framework based on Google's Material Design Specifications. As such, it uses arrowless tooltips like this:
According to the guideline:
Tooltips don’t have directional arrows; instead, they rely on motion emanating from the source to convey direction.
Maybe that'll do in mobile, but in complex web applications with multiple interactive elements on screen it seems a bit overconfident to assume the user will be always catch where the tooltip came from. In such cases removing the arrow may hinder recognizing the tooltip's source.
I'd like to ask the Angular Material to consider adding arrows to their tooltips but since it goes against the now almost sacred Material Design guidelines, I like to ask here if there are any valid reasons to suppress tooltip arrows. Any research about tooltip usability would also be of help.